Experimental and Clinical Immunology Laboratory, Division of Nephrology, Federal University of São Paulo, Escola Paulista de Medicina, São Paulo, Brazil.
Cell Transplant. 2012;21(8):1727-41. doi: 10.3727/096368911X623925. Epub 2012 Feb 2.
Adipose tissue-derived stem cells (ASCs) are an attractive source of stem cells with regenerative properties that are similar to those of bone marrow stem cells. Here, we analyze the role of ASCs in reducing the progression of kidney fibrosis. Progressive renal fibrosis was achieved by unilateral clamping of the renal pedicle in mice for 1 h; after that, the kidney was reperfused immediately. Four hours after the surgery, 2 × 10(5) ASCs were intraperitoneally administered, and mice were followed for 24 h posttreatment and then at some other time interval for the next 6 weeks. Also, animals were treated with 2 × 10(5) ASCs at 6 weeks after reperfusion and sacrificed 4 weeks later to study their effect when interstitial fibrosis is already present. At 24 h after reperfusion, ASC-treated animals showed reduced renal dysfunction and enhanced regenerative tubular processes. Renal mRNA expression of IL-6 and TNF was decreased in ASC-treated animals, whereas IL-4, IL-10, and HO-1 expression increased despite a lack of ASCs in the kidneys as determined by SRY analysis. As expected, untreated kidneys shrank at 6 weeks, whereas the kidneys of ASC-treated animals remained normal in size, showed less collagen deposition, and decreased staining for FSP-1, type I collagen, and Hypoxyprobe. The renal protection seen in ASC-treated animals was followed by reduced serum levels of TNF-α, KC, RANTES, and IL-1α. Surprisingly, treatment with ASCs at 6 weeks, when animals already showed installed fibrosis, demonstrated amelioration of functional parameters, with less tissue fibrosis observed and reduced mRNA expression of type I collagen and vimentin. ASC therapy can improve functional parameters and reduce progression of renal fibrosis at early and later times after injury, mostly due to early modulation of the inflammatory response and to less hypoxia, thereby reducing the epithelial-mesenchymal transition.
脂肪组织来源的干细胞(ASCs)是一种具有再生特性的有吸引力的干细胞来源,其特性类似于骨髓干细胞。在这里,我们分析了 ASCs 在减少肾脏纤维化进展中的作用。通过单侧夹闭小鼠肾蒂 1 小时来实现进行性肾纤维化;之后,肾脏立即再灌注。手术后 4 小时,腹腔内给予 2×10(5)个 ASCs,在治疗后 24 小时和接下来的 6 周内的其他时间点进行随访。此外,动物在再灌注后 6 周时用 2×10(5)个 ASCs 治疗,并在 4 周后处死,以研究间质纤维化已经存在时的治疗效果。再灌注后 24 小时,ASC 治疗的动物表现出肾功能障碍减轻和再生管状过程增强。在 ASC 治疗的动物中,肾 mRNA 表达的 IL-6 和 TNF 减少,而 IL-4、IL-10 和 HO-1 的表达增加,尽管通过 SRY 分析在肾脏中未发现 ASCs。正如预期的那样,未治疗的肾脏在 6 周时缩小,而 ASC 治疗的动物的肾脏保持正常大小,胶原沉积减少,FSP-1、I 型胶原和 Hypoxyprobe 的染色减少。在 ASC 治疗的动物中观察到的肾保护作用后,血清中 TNF-α、KC、RANTES 和 IL-1α 的水平降低。令人惊讶的是,在动物已经表现出纤维化的 6 周时用 ASCs 治疗,可改善功能参数,观察到较少的组织纤维化和 I 型胶原和波形蛋白的 mRNA 表达减少。ASC 治疗可以在损伤后早期和晚期改善肾功能参数并减少肾脏纤维化的进展,主要是由于早期调节炎症反应和减少缺氧,从而减少上皮-间充质转化。